1. Field of the Invention
This invention relates to a retaining construction for retaining connection terminals, used for electrically connecting a wire harness in an automobile or the like, within a connector housing, and more particularly to a double-retaining connector in which the connection terminals are retained in a double manner by a preset-type terminal retainer which is inserted into the connector housing before the connection terminals are inserted respectively into terminal receiving chambers.
2. Related Art
Conventional double-retaining connectors for preventing connection terminals that are inserted into a connector housing from being withdrawn are disclosed in Japanese Patent Examined Publication No. 5-4789 and Japanese Patent Unexamined Publication No. 2-158067. These are commonly known as front spacer types. In these conventional housings, a terminal retainer is inserted into a connector housing from a front end thereof. A rear holder type is disclosed in Japanese Patent Unexamined Publication No. 4-366571, for example.
A conventional front spacer type is shown in FIG. 7. A male connector housing A made of a rigid synthetic resin is fitted on a mating female connector housing (not shown), and has a locking arm 21 and a waterproof hood 22 provided on an outer peripheral portion thereof.
A spacer B serving as a terminal retainer is first partially inserted into the male connector housing A from a front end thereof, and is provisionally held. At this time, lock pawls 26a, formed on a provisional lock plate 26 having a top plate 28 for closing upper sides of terminal receiving chambers 23, are received in a gap V between side walls 24 of the terminal receiving chambers 23. A stopper 29a, formed on a central portion of a lower surface of a horizontal base plate portion 29, fits in a notched portion 25.
Thereafter, a connection terminal 36 is inserted into the terminal receiving chamber 23 from a rear end of the connector housing A. The connection terminal includes an electrical contact portion 38, a wire connection portion 39 having a wire W clamped thereto, and a waterproof plug 37 fitted on a rear end portion thereof. At this time, the connection terminal 36 is primarily retained by an elastic arm (not shown) provided within the terminal receiving chamber 23.
Finally, the spacer B is further inserted so as to be completely retained. Each retaining projection 27a, formed on an elastic terminal retaining plate 27 at the front end of the horizontal base plate portion 29, engages a retaining hole 38a in the corresponding connection terminal 36. The connection terminal 36 is thereby doubly retained within the terminal receiving chamber 23.
A rear holder type is shown in FIG. 8. A rear holder D serving as a terminal retainer is first partially inserted into a retainer mounting chamber 45 provided at a rear end of a female connector housing C made of a synthetic resin, and is provisionally held. More specifically, the rear holder D enters the retainer mounting chamber 45 in such a manner that retaining grooves 49 in the rear holder D are guided respectively by retaining protuberances 58 formed respectively on inner surfaces of side walls 43 of the connector housing C. At this time, a recessed portion 53 in a lower surface of the rear holder D is supported by a guide tongue 64. Two retaining levers 51 enter retaining chambers 59, respectively, and retaining projections 48c of lock arms 48 are slidably engaged respectively by tapering surfaces 57a of retaining portions 57, and are flexed inwardly. Then, the retaining projections 48c slide past the tapering surfaces 57a, respectively, and positioning projections 63 are engaged with the front surface of the rear holder D, thereby provisionally retaining the rear holder.
Then, a male connection terminal E, connected to one end of a wire W, is inserted through an opening 47 into a terminal receiving chamber 41 in a housing body A.sub.1 having at its upper surface a lock chamber 42 for receiving a lock arm of a mating connector housing (not shown). At this time, a retaining lance (not shown), providing within the terminal receiving chamber 41, is engaged in a retaining hole 68 in the connection terminal E, thereby retaining this terminal primarily.
Finally, the rear holder D is urged upwardly from the lower side, so that retaining pawls 51a of the retaining levers 51 move into respective retaining holes 60 past respective provisionally-retaining projections 61 in the respective retaining chambers 59. Retaining projections 50 are respectively supported by the retaining projections 58, and rear holder D is thus fully retained. A wire clamping portion 67 of the connection terminal E is retained by the rear holder D, so that the connection terminal E is doubly retained.
In the front spacer type shown in FIG. 7, in the provisionally-retained condition, part of the spacer B is projected from the front end face of the connector housing A. A problem develops in that before the connection terminals 36 are inserted, the spacer B is urged into the completely-retained condition by an external force developing due to a packing arrangement or when handling the connector. Therefore, in order to insert the connection terminals 36, it is necessary to withdraw the spacer B held in the completely-retained condition, and the efficiency of mounting of the connection terminals 36 is greatly lowered.
In the rear holder type shown in FIG. 8, since the double retaining is effected utilizing the wire clamping portion 67 formed at the rear end of the connection terminal E, the front end of the rear holder D and the rear end of the wire clamping portion 67 always need to be abutted against each other. Therefore, in view of the length of the connection terminal E, it is necessary to form the abutting portion thereof into a slanting configuration, and the configuration becomes complicated. This results in a problem that the costs of the design and manufacture are increased.
With the above problems in view, it is an object of this invention to provide a double-retaining connector in which a double-retaining operation can be effected easily and positively, and a retaining portion will not be influenced by an external force and so on.